Tektro Auriga E-Sub Hydraulic Disc Brake Set For E-Bike - BlackTektro Auriga E Sub Hydraulic Disc Brake Set For E Bike Black This disc brake features a forged aluminium construction, which makes it capable of handling the increased speeds and torque levers produced by E bike motors. Keeping you in control, this hydraulic disc brake's caliper is equipped with an open system with dual pistons. This means you'll benefit from its larger pad area, which absorbs more braking pressure on your electric bike adventures.